U.S. patent application number 11/403095 was filed with the patent office on 2007-10-11 for volumetric measurement and visual feedback of tissues.
This patent application is currently assigned to SDGI Holdings, Inc.. Invention is credited to Jeetendra Bharadwaj, William T. Donofrio, Carlos E. Gil, Jeffrey H. Nycz.
Application Number | 20070238998 11/403095 |
Document ID | / |
Family ID | 38442548 |
Filed Date | 2007-10-11 |
United States Patent
Application |
20070238998 |
Kind Code |
A1 |
Nycz; Jeffrey H. ; et
al. |
October 11, 2007 |
Volumetric measurement and visual feedback of tissues
Abstract
Apparatus and methods for assessing tissue characteristics such
as the dimensions and volume of an osteolytic lesion are disclosed.
The apparatus may utilize ultrasound to provide visual and
volumetric feedback related to a lesion or other tissue. Further
the apparatus may be utilized to determine whether the lesion has
been completely removed and filled with the appropriate amount of
graft material.
Inventors: |
Nycz; Jeffrey H.;
(Collierville, TN) ; Gil; Carlos E.;
(Collierville, TN) ; Donofrio; William T.;
(Andover, MN) ; Bharadwaj; Jeetendra; (Memphis,
TN) |
Correspondence
Address: |
HAYNES AND BOONE, LLP
901 MAIN ST
SUITE 3100
DALLAS
TX
75202
US
|
Assignee: |
SDGI Holdings, Inc.
Wilmington
DE
|
Family ID: |
38442548 |
Appl. No.: |
11/403095 |
Filed: |
April 11, 2006 |
Current U.S.
Class: |
600/437 |
Current CPC
Class: |
A61B 8/56 20130101; A61B
8/0875 20130101; A61B 8/4281 20130101; A61B 8/4472 20130101 |
Class at
Publication: |
600/437 |
International
Class: |
A61B 8/00 20060101
A61B008/00 |
Claims
1. A coupling apparatus for use with an ultrasonic probe in
evaluation of a lesion of a bone having an artificial implant,
comprising: a coupling attachment having a body formed of an
ultrasonic conductive material, said body having an internal wall
defining a cavity adapted to receive a portion of the ultrasonic
probe and an external surface, wherein said external surface is
configured to engage a substantial portion of the artificial
implant.
2. The apparatus of claim 1, wherein the artificial implant is an
acetabular cup.
3. The apparatus of claim 1, wherein said coupling attachment mates
with a hand-held ultrasound device for detecting indicators of a
lesion.
4. The apparatus of claim 3, wherein the hand-held ultrasound
device removably mates with the coupling attachment.
5. The apparatus of claim 4, wherein the coupling attachment is
disposable.
6. The apparatus of claim 3, wherein at least a portion of the
surface of the coupling attachment is malleable to conform to the
implant.
7. The apparatus of claim 3, wherein the artificial implant has an
internal socket and said external surface of the coupling
attachment is sized to mate with a specific size socket of the
artificial implant.
8. The apparatus of claim 6, wherein the malleable surface of the
coupling attachment is adapted for conductive contact with the
artificial implant.
9. The apparatus of claim 8, wherein the artificial implant is
adapted to transmit or receive ultrasound signals when in
conductive contact with the coupling attachment.
10. The apparatus of claim 8, further including a flowable coupling
media, wherein the conductive contact between the coupling
attachment and the artificial implant is facilitated by a coupling
media.
11. The apparatus of claim 10, wherein the coupling media is a
liquid.
12. The apparatus of claim 7, further including a plurality of
coupling attachments of varying sizes.
13. The apparatus of claim 3, wherein a portion of the hand-held
ultrasound device is disposable.
14. The apparatus of claim 3, wherein said hand-held ultrasound
device includes an output signal indicative of sensed reflected
signals, and further including: a processor for developing at least
a portion of a 3-D representation of the lesion based on the output
signal from the hand-held ultrasonic device; and a display
connected to the processor for displaying at least one
characteristic of the lesion representation.
15. The apparatus of claim 14, wherein the characteristic is a
volume of the lesion.
16. The apparatus of claim 14, wherein the characteristic is a
shape of the lesion.
17. The apparatus of claim 16, wherein the processor is further
adapted to formulate a 3-D model of the lesion.
18. The apparatus of claim 17, wherein the display is adapted to
display at least one view of the 3-D model of the lesion.
19. The apparatus of claim 14, wherein the processor and the
display are components of a computer.
20. The apparatus of claim 14, wherein the processor is a part of
the hand-held ultrasound device.
21. The apparatus of claim 20, wherein the display is a part of the
hand-held ultrasound device.
22. The apparatus of claim 14, wherein the hand-held ultrasound
device is adapted for wireless communication with the
processor.
23. A system for providing visual feedback of a lesion of a bone,
comprising: a hand-held ultrasound device adapted to transmit a
signal into a bone, receive reflected signals indicative of
inconsistency in the bone and produce a corresponding output
signal; a processor in communication with said hand-held ultrasound
device and adapted to receive said output signal, said processor
configured to formulate a 3-D model of the lesion based on the
output signal, said processor providing a display signal; and a
display device in communication with said processor and responsive
to said display signal to display at least one view of the 3-D
model of the lesion.
24. The system of claim 23, wherein the processor is further
configured to calculate a volumetric measurement of the lesion.
25. The system of claim 24, wherein the display is adapted for
displaying the volumetric measurement.
26. The system of claim 23, wherein the ultrasound device is
further adapted to determine a location of a surgical instrument
relative to the lesion.
27. The system of claim 26, wherein the display is adapted to show
the relative location of the surgical instrument to the lesion.
28. The system of claim 27, further including an image guided
surgery system adapted to guide the surgical instrument to the
lesion based upon the location of the surgical instrument relative
to the lesion.
29. The system of claim 28, wherein the surgical instrument is
adapted to remove at least a portion of the lesion.
30. A method of assessing a lesion of a bone, comprising: providing
an ultrasound device, a processor, and a display device; activating
the ultrasound device adjacent the lesion; sensing the signals
reflected from the bone and lesion; processing the reflected
signals to generate at least a portion of a 3-D model of the
lesion; and displaying at least a portion of the 3-D model of the
lesion.
31. The method of claim 30, further including calculating a volume
of the lesion in response to the reflected signals.
32. The method of claim 31, further including determining the
appropriate amount of bone filler required to fill the void based
upon the volume of the lesion.
33. The method of claim 30, further including debriding any lesion
material detected.
34. The method of claim 33, further including after said debriding,
detecting any remaining lesion material.
35. The method of claim 30, wherein prior to said activating, the
user applies a first force on the area adjacent the lesion, and
further including after said sensing, applying a second force
different than the first force on the area adjacent the lesion,
activating the ultrasound device adjacent the lesion for a second
reading; and sensing a second set of reflected signals from the
bone and lesion, wherein said processing includes comparing said
the signals reflected from the bone and lesion under the first
force with the second set of reflected signals sensed under the
second force.
Description
TECHNICAL FIELD
[0001] The present disclosure is directed to improved
instrumentation and methods for assessing characteristics of a
tissue. More particularly, in one aspect the present disclosure is
directed toward instruments and methods for assessing
characteristics of a lesion.
BACKGROUND
[0002] The present disclosure relates to the assessment of various
characteristics of tissues, including the size and dimensions of
osteolytic lesions. Joint prostheses often include an articulating
surface composed of a material designed to minimize the friction
between components of the joint prostheses. For example, in a hip
prosthesis the femoral component is comprised of a head (or ball)
and a stem attached to the femur. The acetabular component is
comprised of a cup (or socket) attached to the acetabulum and most
often includes a polyethylene articulating surface. The
ball-in-socket motion between the femoral head and the acetabular
cup simulates the natural motion of the hip joint and the
polyethylene surface helps to minimize friction during articulation
of the ball and socket. However, this articulation has been shown
to release submicron particle wear debris, often polyethylene wear
debris. The release of this debris into the body has been shown to
lead to the development of osteolytic lesions.
[0003] Current techniques for treating lytic and cancerous lesions
include debriding the lesion and filling the remaining defect with
graft materials. Currently surgeons lack a convenient and accurate
way to confirm the exact location of the lesion, whether the lesion
has been completely removed, and whether the remaining void has
been properly filled with graft material. Further, advanced
treatment options use osteoinductive and osteoconductive materials
to heal the lesion. These materials require an accurate assessment
of the volume and shape of the lesion to ensure that the
appropriate amount of biological agent is introduced into the
lesion to promote rapid bone growth and healing.
[0004] Therefore, there remains a need for improved instruments and
methods of evaluating characteristics of tissue and, in particular,
bone lesions.
SUMMARY
[0005] In one embodiment, a system for determining a characteristic
of a lesion of a bone is provided. The system includes a hand-held
ultrasound device for detecting indicators of a lesion, a processor
for determining a characteristic of the lesion based on the
detected indicators, and a display for displaying a representation
of the characteristic. In one aspect, a coupling attachment is
provided to enable effective conductive coupling between the
ultrasound device and the bone.
[0006] In another embodiment, a method of treating a lesion of a
bone is provided. The method includes providing an ultrasound
device, a processor, and a display. The method includes sensing the
signals of the ultrasound device reflected from the bone and
lesion, determining a lesion model based on the sensed signals, and
displaying at least one characteristic of the lesion model.
[0007] Further aspects, forms, embodiments, objects, features,
benefits, and advantages of the present invention shall become
apparent from the detailed drawings and descriptions provided
herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a front view of one embodiment of a system for
determining a characteristic of a lesion of a bone in use with an
artificial acetabular cup.
[0009] FIG. 2 is an enlarged front view of a portion of FIG. 1.
[0010] FIG. 3 is an enlarged side view of a portion of FIG. 1.
DESCRIPTION
[0011] For the purposes of promoting an understanding of the
principles of the present disclosure, reference will now be made to
the embodiments illustrated in the drawings, and specific language
will be used to describe the same. It will nevertheless be
understood that no limitation of the scope of the disclosure is
intended. Any alterations and further modifications in the
described devices, instruments, methods, and any further
application of the principles of the disclosure as described herein
are contemplated as would normally occur to one skilled in the art
to which the disclosure relates.
[0012] Referring now to FIGS. 1-3, there is shown a system 100 for
assessing the volume and dimensions of an osteolytic lesion. FIG. 1
shows the system 100 being utilized to assess an osteolytic lesion
12 of a patient's acetabulum 10 where the patient has an artificial
hip prosthesis. The hip prosthesis includes an artificial
acetabular cup 20. The system 100 includes a hand-held ultrasonic
device 110, a processor 140, and a display 150. Although shown
separately, the processor may be incorporated into the hand-held
device 110, the display 150, or be a stand alone unit. For example,
in one embodiment the display and the processor are parts of a desk
top computer or similar device. Further, in some embodiments, the
display 150 is incorporated into the hand-held device 110. Thus, in
at least one embodiment the system 100 consists of a hand-held
device that incorporates both the processor 140 and the display
150. Examples of similar systems are disclosed in U.S. Patent
Applications filed Feb. 17, 2006 as Ser. No. 11/356,643 entitled
"Surgical Instrument to Assess Tissue Characteristics," and Ser.
No. 11/356,687 entitled "Sensor and Method for Spinal Monitoring,"
that are herein incorporated by reference in their entirety.
[0013] The hand-held device 110 has a body 112, a proximal end 114,
a distal end 116 and a cable 115 connecting the device to the
processor 140. In FIG. 1, the body 112 is shown as being
substantially cylindrical and elongated. This is merely for
illustrative purposes. The body 112 may take any shape, including
non-cylindrical and non-elongated designs, capable of holding the
electrical and mechanical components of the hand-held device 100.
The body 112 includes a gripping surface 118 for grasping by the
user or engagement with another instrument. The gripping surface
118 may include protrusions, recesses, or other features to
facilitate engagement with another instrument. In one embodiment
the gripping surface 118 is disposed closer to the proximal end 114
than to the distal end 116. A transmitter 120 is disposed adjacent
the distal end 116.
[0014] In some embodiments the transmitter 120 is an ultrasound
device. In that regard, the transmitter 120 is adapted to provide
information or data to the processor 140 through cable 115 that may
be processed to create 3 dimensional ("3-D") models and volumetric
data related to osteolytic lesion 10 using ultrasound. In some
embodiments the transmitter 120 is adapted to produce ultrasound
waves that will pass through a portion of an artificial implant,
such as the acetabular cup 20. In one embodiment, the transmitter
120 consists of an acoustic transducer that is adapted for emitting
acoustic signals and detecting the reflected acoustic signals. The
acoustic transducer may function as a pulse-echo transducer having
a single element for emitting and receiving acoustic signals. The
transmitter 120 includes an energy source for producing or emitting
the acoustic or ultrasound signal and a sensor for detecting the
echo or reflected signal. In one embodiment, the functions of the
energy source and the sensor are performed by a single component
switched between a transmit mode and a listen mode. In another
embodiment, the transmitter 120 includes two components. The first
component is configured for emitting signals and a second component
is configured to receive or detect the returned signals.
[0015] It is to be understood that ultrasound is a form of
transmitted energy. In alternative embodiments other forms of
energy and different frequencies are used, such as other types of
acoustics, lasers, visible light, radio frequency, microwaves,
etc., provided they can be transmitted into the lesion and/or
tissue. For instance, the signals disclosed in the present
embodiment are in the frequency range of ultrasonic signals. In
some high resolution systems of the present disclosure, the
frequency can range from 20 KHz up to and exceeding 300 MHz. For
example, these frequencies may be used in acoustic microscopic
instrument applications. In one aspect of the present disclosure,
the frequency range is between 1 MHz to 15 MHz. Still further, the
energy source may be any source capable of transmitting energy into
the affected region to obtain characteristics of the tissue. For
example, in some embodiments the energy source utilizes RF energy
in the range from 400 KHz up to 10 GHz. Still further, in some
embodiments the energy source utilizes a light source generating
non-coherent light, coherent (laser) light, or a combination of the
two.
[0016] The strength and frequency of the signal can be varied
depending on the type of tissue being evaluated. Further, the
strength and frequency of the signal may be varied to enhance the
accuracy of evaluation of a lesion boundary. For instance, in one
aspect the system 100 evaluates the lesion void with multiple
energy beams with different frequencies and then integrates or
combines the sensed signal information utilizing the processor to
best approximate the size and location of the void. Further, in
another aspect the energy beam or signal is shaped for optimum
performance and in some embodiments are focused beams, such as
beams with a substantially cylindrical or conical shape. As shown
in FIGS. 2 and 3, the osteolytic lesion 12 may have an irregular
boundary 14 between the good bone and the lesion. In still another
aspect, the signal is adapted to precisely detect the contours of
the boundary 14. This is accomplished by such means as using a
phased array of transducers, utilizing fiducial markers in
combination with the signals, or any other suitable means. In an
additional embodiment, one or more secondary or ancillary acoustic
energy sources separate from the transmitter 120 are applied to the
body near the boney area of interest. The energy transmitted by
these secondary sources passes through or reflects from the bone
and lesion and is sensed by the transmitter 120. This additional
information is included in the data used to create a 3-D model
representative of at least a portion of a lesion.
[0017] To increase the efficiency and accuracy of the transmitter
120, and in particular the transmission of signals into the tissue,
the distal end 116 of the hand-held device 110 is shaped to
substantially match the contours of a surface of the tissue or a
corresponding implant such that the hand-held device and the tissue
or implant are in conductive contact. That is, the hand-held device
and implant are in sufficient conductive contact, not necessarily
direct contact, to facilitate transmission of energy signals into
the osteolytic lesion and surrounding tissue. In one embodiment,
the exterior of the distal end 116 of the hand-held device 110 is
adapted to selectively engage a coupling attachment 122 formed of
an ultrasonic conductive material that is shaped to mate with the
acetabular cup 20, as shown in FIG. 1. The coupling attachment 122
has an internal cavity adapted to receive at least a portion of
distal end 116. This internal cavity may have a fixed geometry or
may include a malleable material such as an elastomeric material
such that the internal cavity can conform to different sizes and
shapes of distal ends 116 on the hand-held device as may occur from
different manufacturers. Further, in another aspect the system 100
includes a plurality of coupling attachments 122 having different
shapes and sizes corresponding to different types and sizes of
acetabular cups to effectively transmit acoustic energy through the
coupler while generating few, if any, unwanted artifacts. The
appropriate shape and size of coupling attachment 122 is chosen
based on the patient and/or the size of the artificial implant. In
a further aspect, a series of coupling attachments 122 are shaped
to precisely mate with a specific type model of acetabular cup from
a specific manufacturer. A series of coupling attachments 122 is
provided to match-up with more than one model of acetabular cup,
including those made by different manufacturers. Further, although
the illustrated implant appears to have a substantially uniform
curvature, it is contemplated that in alternative embodiments the
coupling attachment will have an asymmetrical form to match a
similar asymmetrical form on the implant.
[0018] In some embodiments the coupling attachment 122 is at least
partially malleable to facilitate more intimate coupling with the
implant or tissue of the patient by conforming to the surface. The
malleable material may be a moldable putty type material, an
elastomeric material such as PORON.RTM. foam or silicon, a gel or
other suitable materials. Thus, the coupling attachment 122 need
not always be specifically designed to match a particular implant.
Rather, in these embodiments the coupling attachment 122 has at
least an external surface that is malleable to mate with numerous
implants of different shapes and sizes. In a further embodiment, a
coupling fluid (not shown) is provided between the coupling
attachment 122 and the artificial implant. In this form, the
coupling attachment 122 is in enhanced conductive communication
with the implant via a coupling fluid. The coupling fluid may be
used to increase the efficiency of the transmission of energy
signals, including ultrasound, from the instrument through the
implant and into the bone. Also, in some embodiments the distal end
116 itself of the hand-held device 110 is shaped to match the
corresponding surface without the need for a coupling
attachment.
[0019] The coupling attachment 122 is adapted for placement at the
distal end 116 such that when the system 100 is in use the
hand-held unit 100 can emit a signal or other type of energy wave
into the tissue being monitored and receive an echo or return
signal. To this end, in one embodiment, the coupling attachment 122
includes a conductive surface. Conductive surface in this context
does not require, but may include electrical conductivity.
Conductive surface in this context is intended to mean a surface
configured to facilitate the emitting and receiving of the
ultrasound or other energy signals. Thus, the surface may serve as
a transducer to emit the signals or receive the signals, or the
surface may simply be transmissive allowing the signals to pass
through. In some embodiments, the acetabular cup 20 or other
artificial implant is utilized as the conductive surface to
facilitate transmission of the signals into the tissue. In this
way, the acetabular cup 20 is a part of the system 100 in some
embodiments. That is, in some embodiments the hand-held device 110
is coupled to the acetabular cup 20 via coupling attachment 122
such that the acetabular cup is utilized to transmit and receive
the signals. Other types of implants besides acetabular cups may be
used to transmit and receive the signals. In some embodiments, the
signals merely pass through the acetabular cup 20.
[0020] Consider the case of an osteolytic lesion 12 of the
acetabulum 10, as shown in FIGS. 1 and 2. An appropriately sized
coupling attachment 122 is mounted on distal end 116 and is placed
in conductive contact with a surface 22 of the artificial
acetabular cup 20. Conductive contact implies that the coupling
attachment 122 and, therefore, the transmitter 120 of the hand-held
device 110 are in sufficient contact, either direct or indirect,
with the acetabular cup 20 to emit a signal or beam into the lesion
and receive a reflected signal from a boundary 14 between the
lesion and the healthy bone of the acetabulum 10. As discussed
above, in some embodiments the acetabular cup 20 facilitates the
emission or receiving of signals. In other embodiments, the signals
merely pass through the acetabular cup 20. In one aspect, the
coupling attachment 122 is adapted for conductive contact with the
acetabular cup 20 using a coupling medium, such as coupling liquid
or other substance. In another aspect, the coupling attachment 122
is adapted for direct contact with the lesion 12 after removal of
the artificial acetabular cup 20. Further, in some embodiments the
transmitter 120 is adapted for direct contact with the acetabular
cup 20 or the lesion 12. In other embodiments, particularly where
the osteolytic lesion 12 or other tissue feature is located within
the acetabulum 10 or other tissue, the coupling attachment 122 is
formed from an appropriate material and shaped to pierce through a
portion of the acetabulum to become in direct conductive contact
with the osteolytic lesion 20 as shown more fully in U.S. patent
application Ser. No. 11/356,687 filed Feb. 17, 2006 incorporated
herein by reference.
[0021] The transmitter 120 emits an ultrasound signal 130 into the
osteolytic lesion 12 through coupling attachment 122 and the
acetabular cup 20. The ultrasound signal 130 will pass through the
lesion 12 until it arrives at the interface between the lesion and
healthy bone, illustrated by boundary 14. At that point, a portion
of the ultrasound signal 130 will reflect off of the boundary 14.
This reflected signal is the echo or return signal 132 that will be
received by the system 100 for determining the characteristics of
the lesion, including size, volume and shape. In one embodiment,
based on the time delay of the return signal 132 and the assumed
constant speed of the acoustic signal in the lesion, the depth of
the osteolytic lesion 12 at various points may be determined by the
signal processor. This can be utilized to determine the shape and
position of the lesion 12. The signal processor may also utilize
this information to determine the volume of the lesion 20. It
should be noted that determining volumetric measurements are
intended to include approximations and estimations of the actual
volume as well as precise determinations of volume. Further, the
volume estimation may be based on the corresponding amount of bone
filler required to fill the void once the lesion is removed, such
as a small INFUSE.RTM. bone graft kit from Medtronic, Inc. or other
similar bone growth stimulators, rather than a numerical
representation, such as 36 cc.
[0022] The reflected signals 132 are used by the signal processor
to determine the boundary of the lesion and to determine the volume
based on the points defining the lesion boundary. In one
embodiment, the boundaries are compared to one or more known
geometric shapes of known volume to determine the best fit and
thereby determine the best approximation of the volume of the
lesion. For example, but without limitation to other shapes, the
geometric shapes include spheres, cylinders, cubes, pyramids and
cones. Further, more than one shape of different sizes may be used
to approximate the lesion shape and volume. For example, a series
of small cubes may be stacked in virtual space within the void
boundaries to closely approximate the actual sensed volume. In one
embodiment, the volume determination is made by the surgeon based
upon the boundaries of the lesion. In another embodiment, the
signal processor calculates both the boundaries and the volume of
the lesion 12.
[0023] In some embodiments the transmitter 120 first emits a broad
signal that travels into a wide area of the acetabulum 10. Then
based upon the reflected signal from the broad signal, a narrower
signal is focused upon an area where indicators of an osteolytic
lesion were detected. This process is iterated until a beam of
appropriate size is transmitted to detect the features of the
osteolytic lesion. Where multiple lesions are detected the signal
may focus upon one lesion at a time, repeating the process for the
additional lesions after obtaining features of the first lesion.
Focusing the signal on a specific location may be automatically
performed based on calculations performed by the signal processor,
manually performed by the operator, or a combination of the two.
For example, the operator may utilize a 3-D display, discussed
below, to identify generally the presence of a lesion and then
focus the signal to obtain more information about the lesion such
as its size, shape, and density. In these ways, the system 100 may
focus in on the osteolytic lesion to obtain the most precise data
and information available. Further, in other aspects, the user
moves the location of transducer 120 to various points in three
dimensional space and the processor determines volume and
boundaries of the lesion based on the difference in reflected
signals from the plurality of locations. In a further embodiment,
the user applies a compressive force to the hand held probe that is
transmitted to the bone and the lesion. A first ultrasonic reading
is taken with the hand held probe or other tool compressing the
bone and/or lesion with a first pressure. A second ultrasonic
reading is taken with the hand held probe or other tool compressing
the bone and/or lesion with a second pressure. The first and second
ultrasonic readings are compared and the difference in the sensed
characteristics under varying pressure is utilized to create at
least a portion of a 3-D model representing the lesion. In still a
further embodiment, a plurality of coupling attachments are
provided with different surface contact areas. The user initial
starts with a large surface contact coupler for the general
ultrasonic survey of the area of interest. The user then selects a
coupler having a smaller surface contact area, much less than the
surface area of the implant such as shown in FIG. 1, and applies
the coupler to the area of interest. If still further more detailed
information is desired, a still smaller contact surface area
coupler may be attached to the hand held probe and utilized to
interrogate the lesion.
[0024] In some embodiments, the system 100 is used to create a 3-D
image or model of the osteolytic lesion and surrounding bone from
which the lesion may then be evacuated. The 3-D image may be viewed
by the surgeon on the display 150. A second reading may be taken
after debridement of the lesion. Then, based on the second reading,
any remaining lesion may be identified and removed. In this way,
the system 100 not only allows the physician to determine if any
lesion remains, but also know precisely where any unwanted tissue
remains. This process can be iterated until the lesion is
completely removed. This process allows for successful removal of
all of the undesirable tissue, which in the case of osteolytic
lesions has been difficult to determine in the past.
[0025] Where the electronic instrumentation 100 is utilized to
check for the complete removal of the lesion 20 after debridement,
a coupling media or filler material is used to fill the void. For
example, in one embodiment the void is filled with a saline
solution or other conductive substance such that the electronic
instrumentation 100 may detect the boundaries between the saline
and the lesion 20 to determine if the lesion has been fully
removed. In one embodiment, the coupling media is a flowable
material with known acoustic properties that are easily
distinguishable from the lysis and surrounding bone. For example,
but without limitation to other materials, the coupling media
includes saline solution, blood, plasma, bone paste, bone wax,
allograft, autograft, demineralized bone, BMP in a carrier matrix,
mineralized granules, and bone cement. In an additional aspect, the
system 100 is used to detect proper packing of the completely
debrided void with bone filler material disposed between the bone
filler material and the boney boundary. To this end the system may
detect any remaining voids or the presence of foreign
materials--such as the filler materials--in comparison to the
original lesion.
[0026] Alternatively, for less defined lesion boundaries, reflected
energy signals are processed to determine a gradient profile for
the transitional tissue between the healthy bone and the homogenous
lesion material to determine bone integrity or condition.
Information from the reflected signals is used to by the health
care provider to determine the extent of debridement desired for a
successful procedure. In one embodiment, the system evaluates the
boundary of the lesion to determine the gradient between the
natural healthy tissue well outside the lesion, the substantially
homogenous lesion material, and the transitional tissue of
potentially compromised tissue extending between the lesion and the
healthy tissue. In one form, the processor is programmed to select
a debridement and volume boundary where the transitional tissue
gradient is between 100% and 50% healthy tissue. In another form
for cancerous lesion removal, the processor is programmed to set
the debridement boundary so it includes a buffer of healthy tissue
outside of the sensed lesion boundary to ensure that all of the
cancerous and pre-cancerous cells are removed.
[0027] The system 100 includes a display 150. Depending on the type
of data being obtained by the system 100 the display 150 may take
on different forms. Where the system 100 is configured to create
3-D models of the tissue and lesion the display 150 must have
sufficient resolution to show the details of the image. Thus, where
3-D images are utilized the display 150 may be a computer monitor,
television, projector, or other display with sufficient output
capabilities. In some embodiments, the system 100 will be adapted
to create 2-D models of the tissue and the display 150 is adapted
accordingly. In such cases, the 2-D images may be derived from the
3-D models. In some embodiments, views of a 3-D model will not be
required and therefore the display 150 may have much lower
resolution. For example, if the display 150 is adapted to show the
estimated size of the lesion, such as "36 cc," a small liquid
crystal display may be sufficient. Without limitation to detecting
smaller or larger lesions, it is contemplated that the system 100
detects lesion sizes ranging from 5 cc-100 cc.
[0028] In some embodiments, it will not be necessary for the
display 150 to show even the volume of a lesion. In those
situations, the system 100 and the display 150 are adapted to show
an indication of the general size of the lesion, such as small,
medium, large, or extra large. Each size will have a corresponding
range of volumes and possibly an associated surgical kit based on
the amount of grafting material required. In such a case, the
display 150 may be adapted to show a color, an appropriately sized
bar, or a letter (e.g. S, M, L, or XL) corresponding to the size of
the lesion. Thus, there are numerous simple visual displays that
may be used to indicate the size or other data obtained by the
system 100. In addition, in one embodiment the system 100 does not
include a display.
[0029] In lieu of or in addition to display 150, alternative
embodiments of the system include other means of outputting tissue
data in human intelligible form. For example, in one embodiment the
system includes an audible output, such as a speaker, adapted to
provide information to the caretaker. In one embodiment, the
audible output beeps or otherwise indicates the general size of the
lesion or other tissue malformity. Other human intelligible forms,
such as vibrations, are also contemplated as means of outputting
tissue data.
[0030] In one embodiment the system may classify the size of the
lesion based on a kit size related to the amount of grafting
material--such as autograft, allograft, osteoconductive, or
osteoinductive materials--needed to fill the lesion. For example,
but without limitation, in one embodiment the void is filled with a
mixture of bone morphogenic protein (BMP) carrier matrix and
mineralized granules. The carrier is a collagen sponge or paste
including bi-calcium phosphate. The BMP may be included in a
platelet gel or may be recombinant BMP. The mineralized granules
are a homogenous substance or mixture of autograft, allograft,
xenograft, hydroxyl appetite, bi-calcium phosphate, coral or other
materials suitable for implantation. In one aspect a small kit
would be a small INFUSE.RTM. bone graft kit from Medtronic, Inc.
containing a 2.5 mm collagen sponge and a vial of BMP to
reconstitute in solution of 1.5 mg/ml of saline solution. A medium
INFUSE.RTM. bone graft kit would contain a 5.6 mm collagen sponge
and a larger vial of BMP, while a large INFUSE.RTM. bone graft kit
would contain an 8.0 mm collagen sponge and a larger vial of BMP to
reconstitute a solution at 1.5 mg/ml of saline solution.
[0031] As shown in FIG. 1, the hand-held device 110 is wired by
cable 115 to processor 140, which in turn is connected to the
display 150. This wired communication is utilized to transfer data
from the hand-held device 110 to the display 150 and signal
processor. In some embodiments the hand-held device 110 is adapted
for wireless communication with the signal processor 140 and
display 150. In this regard, the hand-held device 110 is configured
to transfer data using RFID, inductive telemetry, acoustic energy,
near infrared energy, "Bluetooth," or computer networks. The
hand-held device 110 transfers data to offload tasks such as the
computing performed by the signal processor, displaying the data,
or storing the data. This is particularly true where the signal
processor and the display are part of a computer system or other
apparatus specifically adapted for processing, storing, and
displaying the information. The hand-held device 110 also includes
a memory and a port for transferring data in one embodiment. In
such an embodiment, the hand-held device 110 may be utilized to
obtain data and then selectively connected to the signal processor
or display.
[0032] The wired communication is also utilized to provide power to
the hand-held device 110. In one aspect, the hand-held device 110
receives power via a Universal Serial Bus ("USB") system. In this
way the hand-held device 110 may be adapted to communicate over a
USB cable with the signal processor and display so as to both
receive power and transmit data. In this way, the hand-held device
100 utilizes the external device to receive power, perform the
signal processing, store data, and display information. Thus, the
external device may be handheld device such as a cell phone, PDA,
or similar type device as well as a laptop or desktop computer.
[0033] In an alternative embodiment the hand-held device 110 is
adapted to receive power from an external source dedicated solely
to providing power. For example, the hand-held device 110 receives
power from a wall socket or other common power source through a
wired connection in some embodiments. To this end, the hand-held
device 110 may itself include a wire adapted to plug into the power
source. On the other hand, the hand-held device 110 may include an
adapter or receiver for selectively connecting to a wired power
supply, such that the instrumentation is not permanently attached
to the wire. In one embodiment, the power supply of the hand-held
device 110 is an internal power source. That is, the power supply
is fully disposed within the hand-held device 110. In such an
embodiment, the internal power source is a battery or a plurality
of batteries.
[0034] It is fully contemplated that the hand-held device 110 be
configured to include as few parts as needed, utilizing the
features of external devices to the full extent possible. This can
be very beneficial where the hand-held device 110 is adapted to be
disposable such that cost is kept to a minimum. In at least one
embodiment the coupling attachment 122 is disposable so that the
coupling attachment is discarded after each use and the remaining
portions of the hand-held device 110 and system 100 are reusable.
In other embodiments the entire hand-held device 110 is disposable.
That is, the hand-held device 110 is designed for use in only one
medical procedure or for a limited amount of time. For example, in
one aspect the hand-held device 110 includes a circuit that breaks
or disconnects if the instrumentation is subjected to autoclaving
or other types of sterilization procedures. The hand-held device
110 may also include a battery with a predetermined life. For
example, the battery may be designed to provide power to operate
the hand-held device 110 for 12 hours after initiation. This would
give the hand-held device sufficient power for long surgical
procedures, yet limit the useful life of the instrumentation to a
single procedure.
[0035] Further, the data from the system 100 may be transmitted to
an image guided surgery (IGS) system such that the data concerning
the tissue properties and three-dimensional void boundaries may be
integrated with the positioning data of the IGS system. Thus, a
composite three-dimensional model showing the tissue type and/or
void boundaries is calculated and may be displayed separately or as
part of a composite image with the IGS display. The data from the
system 100 may be transmitted wirelessly or by wired communication,
or through a data storage device to the IGS system.
[0036] In a further embodiment, the system 100 itself is a
component of an IGS system. In this embodiment, the system 100 is
utilized to map the three-dimensional void boundaries and the
three-dimensional location of the lesion relative to the patient's
body. The IGS system then guides the user to remove all or
substantially all of the lesion based on the sensed data. In an
alternative embodiment, the IGS system includes an automated bone
removal device in communication with the IGS system. The automated
bone removal device is advanced to the lesion site under computer
control, activated to remove the lesion under computer control, and
removed from the lesion site. In a further embodiment, the IGS
system automatically locates the lesion void after debridement and
fills the void with a filler material. Finally, in another
embodiment a sensor is placed in the filler material to verify
complete filling of the void.
[0037] Though the system 100 has been described primarily in
connection with detecting the size of lesions in bone and
determining whether removal of the lesion was successful, the
system according the present invention has many other applications.
In one application, the system 100 is used after filling of the
void with bone filling material to evaluate completeness of the
filling. For example, the difference in material properties between
the native bone, the bone filler and any substance left in the void
can be sensed by the system 100. If a foreign substance, such as
blood, air, saline solution, lesion, tumor, etc., remains after
filling the void the system can detect it, display the information,
and alert the user. In another application, the system 100 is
configured to determine the actual density of tissue, rather than
simply distinguishing between different types of tissue. This may
be particularly advantageous in the treatment of patients with
osteoporosis.
[0038] Although lesion has often been referred to in regards to an
osteolytic lesion, lesion is intended to include any type of
abnormal tissue, malformation, or wound related to a bone or other
tissue, including cancers, voids, tumors, missile injuries,
projectiles, puncture wounds, fractures, etc. For example, in some
embodiments the disclosed system is useful to detect and determine
the size of bone cancer voids, cancer cells, and tumors. Further,
the system is also adapted to detect the presence of healthy tissue
as well. Thus, the electronic instrumentation is adapted to
determine the shape and volume of tissue features, both good and
bad.
[0039] In another aspect, the system is used to remotely probe
suspect tissue and alert the user to the presence of anomalous
tissue based on reflected energy indicating different densities. In
still a further aspect, the system is used to monitor the growth
and healing of soft tissues in 3-D space, such as tendons and
ligaments, as well as bone. In yet a further embodiment, the system
is utilized to detect the location in 3-D space of foreign bodies,
such as bullets, nails, glass, or other objects, in various types
of tissue and particularly associated with penetration wounds. In
one embodiment, the features of the hand-held device are combined
with a grasping instrument such that the detected foreign bodies
may be located, grasped by the instrument, and withdrawn from the
patient.
[0040] Finally, the electronic instrumentation may be configured to
perform a plurality of the various applications described above in
combination. Specifically, the system may include two or more of
the previously described features.
[0041] The foregoing outlines features of several embodiments so
that those skilled in the art may better understand the aspects of
the present disclosure. Those skilled in the art should appreciate
that they may readily use the present disclosure as a basis for
designing or modifying other processes and structures for carrying
out the same purposes and/or achieving the same advantages of the
embodiments introduced herein. Those skilled in the art should also
realize that such equivalent constructions do not depart from the
spirit and scope of the present disclosure, and that they may make
various changes, substitutions and alterations herein without
departing from the spirit and scope of the present disclosure.
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